[PATCH v3 5/9] iommu/arm-smmu-v3: Store SteamIDs in master

Jean-Philippe Brucker
2019-04-17T18:24:44Z

Simplify the attach/detach code a bit by keeping a pointer to the stream
IDs in the master structure. Although not completely obvious here, it does
make the subsequent support for ATS, PRI and PASID a bit simpler.

Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker-5wv7dgnIgG8@public.gmane.org>
---
drivers/iommu/arm-smmu-v3.c | 30 +++++++++++++++---------------
1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 50cb037f3d8a..25ba546cae7f 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -594,6 +594,8 @@ struct arm_smmu_device {
struct arm_smmu_master {
struct arm_smmu_device *smmu;
struct arm_smmu_strtab_ent ste;
+ u32 *sids;
+ unsigned int num_sids;
};

/* SMMU private data for an IOMMU domain */
@@ -1688,19 +1690,18 @@ static __le64 *arm_smmu_get_step_for_sid(struct arm_smmu_device *smmu, u32 sid)
return step;
}

-static void arm_smmu_install_ste_for_dev(struct iommu_fwspec *fwspec)
+static void arm_smmu_install_ste_for_dev(struct arm_smmu_master *master)
{
int i, j;
- struct arm_smmu_master *master = fwspec->iommu_priv;
struct arm_smmu_device *smmu = master->smmu;

- for (i = 0; i < fwspec->num_ids; ++i) {
- u32 sid = fwspec->ids[i];
+ for (i = 0; i < master->num_sids; ++i) {
+ u32 sid = master->sids[i];
__le64 *step = arm_smmu_get_step_for_sid(smmu, sid);

/* Bridged PCI devices may end up with duplicated IDs */
for (j = 0; j < i; j++)
- if (fwspec->ids[j] == sid)
+ if (master->sids[j] == sid)
break;
if (j < i)
continue;
@@ -1709,13 +1710,10 @@ static void arm_smmu_install_ste_for_dev(struct iommu_fwspec *fwspec)
}
}

-static void arm_smmu_detach_dev(struct device *dev)
+static void arm_smmu_detach_dev(struct arm_smmu_master *master)
{
- struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
- struct arm_smmu_master *master = fwspec->iommu_priv;
-
master->ste.assigned = false;
- arm_smmu_install_ste_for_dev(fwspec);
+ arm_smmu_install_ste_for_dev(master);
}

static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
@@ -1736,7 +1734,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)

/* Already attached to a different domain? */
if (ste->assigned)
- arm_smmu_detach_dev(dev);
+ arm_smmu_detach_dev(master);

mutex_lock(&smmu_domain->init_mutex);

@@ -1770,7 +1768,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
ste->s2_cfg = &smmu_domain->s2_cfg;
}

- arm_smmu_install_ste_for_dev(fwspec);
+ arm_smmu_install_ste_for_dev(master);
out_unlock:
mutex_unlock(&smmu_domain->init_mutex);
return ret;
@@ -1883,12 +1881,14 @@ static int arm_smmu_add_device(struct device *dev)
return -ENOMEM;

master->smmu = smmu;
+ master->sids = fwspec->ids;
+ master->num_sids = fwspec->num_ids;
fwspec->iommu_priv = master;
}

/* Check the SIDs are in range of the SMMU and our stream table */
- for (i = 0; i < fwspec->num_ids; i++) {
- u32 sid = fwspec->ids[i];
+ for (i = 0; i < master->num_sids; i++) {
+ u32 sid = master->sids[i];

if (!arm_smmu_sid_in_range(smmu, sid))
return -ERANGE;
@@ -1922,7 +1922,7 @@ static void arm_smmu_remove_device(struct device *dev)
master = fwspec->iommu_priv;
smmu = master->smmu;
if (master && master->ste.assigned)
- arm_smmu_detach_dev(dev);
+ arm_smmu_detach_dev(master);
iommu_group_remove_device(dev);
iommu_device_unlink(&smmu->iommu, dev);
kfree(master);
--
2.21.0